PR #17424 exact-head evidence (b7afc19344c5)

Exact-head evidence for PR #17424 after a clean rebase onto develop at b5eb7e3d52920e08a73fc04a3396d95e27e8fe77.

Includes full-page desktop/mobile screenshots, an H.264 walkthrough, browser validation, the live GitHub leaderboard snapshot, verified skill archive, live AWS Bedrock review, and live candidate installer authorization evidence. The release manifest inventories every other asset by byte count and SHA-256.